Cerebral organoids derived from Sandhoff disease-induced pluripotent stem cells exhibit impaired neurodifferentiation

Maria L Allende,Emily K Cook,Bridget C Larman,Adrienne Nugent,Jacqueline M Brady,Diane Golebiowski,Miguel Sena-Esteves,Cynthia J Tifft,Richard L Proia

doi:10.1194/jlr.m081323

Abstract

Sandhoff disease, one of the GM2 gangliosidoses, is a lysosomal storage disorder characterized by the absence of β-hexosaminidase A and B activity and the concomitant lysosomal accumulation of its substrate, GM2 ganglioside. It features catastrophic neurodegeneration and death in early childhood. How the lysosomal accumulation of ganglioside might affect the early development of the nervous system is not understood. Recently, cerebral organoids derived from induced pluripotent stem (iPS) cells have illuminated early developmental events altered by disease processes. To develop an early neurodevelopmental model of Sandhoff disease, we first generated iPS cells from the fibroblasts of an infantile Sandhoff disease patient, then corrected one of the mutant HEXB alleles in those iPS cells using CRISPR/Cas9 genome-editing technology, thereby creating isogenic controls. Next, we used the parental Sandhoff disease iPS cells and isogenic HEXB-corrected iPS cell clones to generate cerebral organoids that modeled the first trimester of neurodevelopment. The Sandhoff disease organoids, but not the HEXB-corrected organoids, accumulated GM2 ganglioside and exhibited increased size and cellular proliferation compared with the HEXB-corrected organoids. Whole-transcriptome analysis demonstrated that development was impaired in the Sandhoff disease organoids, suggesting that alterations in neuronal differentiation may occur during early development in the GM2 gangliosidoses.

Highlights

Sandhoff disease, one of the GM2 gangliosidoses, is a lysosomal storage disorder characterized by the absence of -hexosaminidase A and B activity and the concomitant lysosomal accumulation of its substrate, GM2 ganglioside
We examined the level of GM2 storage by immunostaining Sandhoff disease cerebral organoid frozen sections, and found the presence of GM2 ganglioside as early as at week 4 of culture, mainly in cells located in areas positive for neuronal 3 tubulin expression (Fig. 3A)
We found a significant increase in the number of BrdU+ DAPI+ cells in Sandhoff disease organoids compared with the isogenic HEXB-corrected organoids at both time points (Fig. 8A)

Summary

Introduction

One of the GM2 gangliosidoses, is a lysosomal storage disorder characterized by the absence of -hexosaminidase A and B activity and the concomitant lysosomal accumulation of its substrate, GM2 ganglioside. It features catastrophic neurodegeneration and death in early childhood. Tay-Sachs disease, and the GM2 activator deficiency (Fig. 1A) are lysosomal storage disorders known as the GM2 gangliosidoses [reviewed in [1]] They are rare autosomal recessive conditions caused by mutations in the HEXB (Sandhoff disease), HEXA (Tay-Sachs disease), or GM2A (GM2 activator deficiency) genes.

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Results

Conclusion